Face recognition in low light conditions for unlocking an electronic device

ABSTRACT

Certain aspects of the present disclosure provide techniques for performing face recognition in low light conditions using an electronic device. One aspect provides a method including determining if a brightness level within a viewing area of the electronic device satisfies a threshold. The method includes increasing a luminance output of the electronic device from a first luminance level to a second luminance level when the brightness level does not satisfy the threshold. The method includes capturing an image at the second luminance level when the brightness level does not satisfy the threshold. The method includes capturing the image at the first luminance level when the brightness level satisfies the threshold. The method includes detecting a face in the image. The method includes determining if the face corresponds to an authorized user. The method includes unlocking the electronic device when the face corresponds to an authorized user.

INTRODUCTION

Aspects of the present disclosure relate to electronic devices, such assmartphones, and more particularly, to techniques for performing facerecognition in low light conditions using an electronic device, such asfor unlocking the electronic device.

Electronic devices, such as mobile devices (e.g., smartphones, tablets,laptops, etc.) may be susceptible to accidental activation while beingcarried. Inadvertent contact (e.g., from a foreign object, user's hand,surface, etc.) with the mobile device (e.g., with the touchscreen, abutton, etc., of the mobile device) may be interpreted as user input,causing undesired actions to be taken on the mobile device.

Accordingly, many mobile devices include a locking feature to preventsuch inadvertent contact from causing undesired actions to be taken onthe mobile device. For example, the mobile device can be locked (e.g.,manually, automatically such as after a period of inactivity, etc.) soit does not respond to user input unless some particular unlockoperation is first performed.

In many cases, the locking feature may alternatively or additionallyprovide security for the mobile device. For example, the unlockoperation may require some form of user authentication that preventsunauthorized users from accessing the mobile device. For example, tounlock the mobile device, a user may need to enter an appropriatepattern, passcode, or password on a touchscreen of the mobile device orbe authorized according to some biometric identification of the user.

In some cases, face recognition is used at a mobile device to unlock themobile device. Many mobile devices include an optical sensor (e.g.,front-facing camera, a charge-coupled device (CCD), complementarymetal-oxide semiconductor (CMOS), etc.) that is configured to capture animage of a user. Further, many such mobile devices are configured to runface recognition algorithms for performing face recognition of a userbased on the captured image of the face of the user. Accordingly, theface recognition of the user may be used as a biometric identificationof the user to unlock the mobile device. If the face of an authorizeduser is recognized, the mobile device unlocks. If the face of anauthorized user is not recognized, the mobile device remains locked.

Use of the optical sensor in a mobile device in low light situations maylead to a low quality image for images captured using the opticalsensor. For example, the optical sensor may have a limited sensorquality (e.g., small pixel size, low resolution, etc.) due to designconstraints of the mobile device. Such an optical sensor may not becapable of capturing enough light during the image capture process,which may lead to a noisy, dark, washed out, flat, and/or improperlycolored captured image. Accordingly, when such a captured image is usedfor face recognition, the face recognition algorithms may not accuratelyrecognize the user in the captured image, and therefore the mobiledevice may not unlock successfully, thereby frustrating the user.

BRIEF SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedface recognition techniques.

One aspect provides a method for performing face recognition in lowlight conditions using an electronic device. The method includesdetermining if a brightness level within a viewing area of theelectronic device satisfies a threshold. The method includes increasinga luminance output of the electronic device from a first luminance levelto a second luminance level when the brightness level does not satisfythe threshold. The method includes capturing an image at the secondluminance level when the brightness level does not satisfy thethreshold. The method includes capturing the image at the firstluminance level when the brightness level satisfies the threshold. Themethod includes detecting a face in the image. The method includesdetermining if the face corresponds to an authorized user. The methodincludes unlocking the electronic device when the face corresponds to anauthorized user.

Another aspect provides an electronic device. The electronic deviceincludes an optical sensor configured to capture one or more imageswithin a viewing area of the optical sensor. The electronic deviceincludes a light emitting component. The electronic device includes aprocessor. The processor is configured to determine if a brightnesslevel within the viewing area of the optical sensor satisfies athreshold. If the brightness level does not satisfy the threshold, theprocessor is configured to: increase a luminance of the light emittingcomponent from a first luminance level to a second luminance level; andcontrol the optical sensor to capture an image at the second luminancelevel. If the brightness level satisfies the threshold, the processor isconfigured to: control the optical sensor to capture the image at thefirst luminance level. The processor is configured to detect a face inthe image. The processor is configured to determine if the facecorresponds to an authorized user. The processor is configured to unlockthe electronic device when the face corresponds to an authorized user.

Another aspect provides a computer readable medium having instructionsstored thereon for causing an electronic device to perform a method forperforming face recognition in low light conditions. The method includesdetermining if a brightness level within a viewing area of theelectronic device satisfies a threshold. The method includes increasinga luminance output of the electronic device from a first luminance levelto a second luminance level when the brightness level does not satisfythe threshold. The method includes capturing an image at the secondluminance level when the brightness level does not satisfy thethreshold. The method includes capturing the image at the firstluminance level when the brightness level satisfies the threshold. Themethod includes detecting a face in the image. The method includesdetermining if the face corresponds to an authorized user. The methodincludes unlocking the electronic device when the face corresponds to anauthorized user.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe related drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the drawings. It is to be noted, however, thatthe drawings illustrate only certain typical aspects of this disclosureand are therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects.

FIG. 1 is a functional block diagram of a mobile device in accordancewith aspects of the present disclosure.

FIG. 2 is an illustration of an example mobile device in accordance withaspects of the present disclosure.

FIG. 3 illustrates example operations for performing face recognitionthat may be performed by an electronic device, in accordance withaspects of the present disclosure.

FIG. 4 illustrates example operations for performing face recognitionthat may be performed by an electronic device, in accordance withaspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processingsystems, and computer readable mediums for performing face recognitionusing an electronic device in low light conditions. Certain aspects aredescribed herein with respect to using a mobile device to perform facerecognition to unlock the mobile device. However, it should beunderstood that the techniques described herein for performing facerecognition may additionally or alternatively be used for authenticatinga user for other purposes than unlocking a mobile device. For example,the techniques for performing face recognition described herein may beused for authenticating a user for a mobile payment, for accessing anapplication, etc. Further, it should be understood that the techniquesdescribed herein may similarly be performed by any suitable electronicdevice, not just a mobile device.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in some other examples. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition to,or other than, the various aspects of the disclosure set forth herein.It should be understood that any aspect of the disclosure disclosedherein may be embodied by one or more elements of a claim. The word“exemplary” is used herein to mean “serving as an example, instance, orillustration.” Any aspect described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects.

FIG. 1 is a functional block diagram of a mobile device 100. Forexample, the mobile device 100 may correspond to any appropriate mobiledevice including a smartphone, mobile phone, tablet, etc. The mobiledevice 100 may be configured to implement some or all of the teachingsdiscussed herein. For example, the mobile device 100 may be configuredto perform face recognition in low light conditions as described herein.The mobile device 100 may further be configured to authenticate a userof the mobile device 100 based on the face recognition performed, suchas to unlock the mobile device 100.

The mobile device 100 includes a processor 110 in data communicationwith a memory 120, and an input/output interface 130. The input/outputinterface 130 is further in data communication with a display 140 (e.g.,liquid crystal display (LCD), organic light emitting diode (OLED),active matrix OLED (AMOLED), etc.) and an optical sensor 105 (e.g.,charge-coupled device (CCD), complementary metal-oxide semiconductor(CMOS), etc.). The display 140 is an example of a light emittingcomponent. The input/output interface 130 is also optionally in datacommunication with a dedicated illumination element 115 (e.g., flash,LED (light emitting diode) light, xenon light, flashtube, etc.). Theillumination element 115 is another example of a light emittingcomponent. The processor 110 is further in data communication with anetwork interface 160. Although described separately, it is to beappreciated that functional blocks described with respect to the mobiledevice 100 need not be separate structural elements. For example, theprocessor 110 and memory 120 may be embodied in a single chip.Similarly, two or more of the processors 110, and network interface 160may be embodied in a single chip. The mobile device 100 may beconfigured to perform the functions described herein. For example, theprocessor 110 may be configured to execute instructions stored in thememory 120 that cause the mobile device 100 to perform the functions andprocesses described herein.

The processor 110 can be a general purpose processor, a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anysuitable combination thereof designed to perform the functions describedherein. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor, aplurality of microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The processor 110 can be coupled, via one or more buses, to readinformation from or write information to memory 120. The processor mayadditionally, or in the alternative, contain memory, such as processorregisters. The memory 120 can include processor cache, including amulti-level hierarchical cache in which different levels have differentcapacities and access speeds. The memory 120 can also include randomaccess memory (RAM), other volatile storage devices, or non-volatilestorage devices. The storage can include, for example, flash memory,flash drives, non-volatile RAM (NVRAM), read only memory, etc.

The processor 110 is also coupled to an input/output interface 130 for,receiving input from and providing output to, devices connected to orintegrated as part of the mobile device 100. Examples of such devicesinclude, but are not limited to, keys, buttons, sensors, switches, apointing device, a remote device, an infrared detector, a camera sensor(e.g., optical sensor 105), a motion detector, a microphone (possiblycoupled to audio processing software to, e.g., detect voice commands),visual output devices such as a touch-screen display (e.g., display140), audio output devices, including speakers, headphones, earphones,and alarms, and haptic output devices, including force-feedback andvibrating devices. The input/output interface 130 may use one or moreprotocols to, wirelessly or through a wired connection, communicate withdevices including but not limited to universal serial bus (USB),FireWire, Thunderbolt, Light Peak, digital video interface (DVI),high-definition multimedia interface (HDMI), video graphics array (VGA),peripheral component interconnect (PCI), etc.

The processor 110 is further coupled to a network interface 160. Thenetwork interface 160 may comprise one or more modems. The networkinterface 160 prepares data generated by the processor 110 fortransmission to a network or another device. The network interface 160may also demodulate data received via the network. The network interface160 can include a transmitter, receiver, or both (e.g., a transceiver).In other aspects, the transmitter and receiver are two separatecomponents. The network interface 160, can be embodied as a generalpurpose processor, a digital signal processor (DSP), an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, or any suitable combination thereofdesigned to perform the functions described herein. The networkinterface 160 may be a wired interface (e.g., Ethernet, local areanetwork (LAN), etc.) and/or a wireless interface (e.g., Long-TermEvolution (LTE), wireless local area network (WLAN), WiFi, code divisionmultiple access (CDMA), 5 G, new radio (NR), etc.), global system formobile communications (GSM), worldwide interoperability for microwaveaccess (WiMax), Bluetooth, etc.).

FIG. 2 is an illustration of an example mobile device 200. The mobiledevice 200, in some aspects, may correspond to a physical implementationof the mobile device 100. As shown, the mobile device 200 is asmartphone type device. The mobile device 200 includes an optical sensor205 (e.g., corresponding to optical sensor 105), a display 240 (e.g.,corresponding to display 140), and optionally a dedicated illuminationelement 215 (e.g., corresponding to illumination element 115). As can beseen, the optical sensor 205, display 240, and dedicated illuminationelement 215 are all facing the same direction. The optical sensor 205,accordingly, may be referred to as a front-facing optical sensor thatfaces the same direction as a display of the mobile device 200.Internally, the mobile device 200 may have other components, such as oneor more of the components described with respect to mobile device 100that perform functions described with respect to mobile device 100. Forexample, the mobile device 200 may be configured to implement some orall of the teachings discussed herein. For example, the mobile device200 may be configured to perform face recognition in low lightconditions as described herein. The mobile device 200 may further beconfigured to authenticate a user of the mobile device 200 based on theface recognition performed, such as to unlock the mobile device 200.

Example Methods and Apparatuses for Performing Face Recognition in LowLight Conditions

Conventional methods for performing face recognition on a mobile devicemay include capturing an image of a user including a face of the userusing a front-facing optical sensor of the mobile device. Further, aprocessor of the mobile device runs a face recognition algorithm forperforming face recognition of the user based on the captured image ofthe face of the user. The face recognition of the user may be used as abiometric identification of the user to unlock the mobile device. If theface of an authorized user is recognized, the mobile device unlocks. Ifthe face of an authorized user is not recognized, the mobile deviceremains locked.

In certain cases, a mobile device may not be able to recognize the faceof an authorized user even when the captured image includes the face ofthe authorized user. For example, the optical sensor may have a limitedsensor quality (e.g., small pixel size, low resolution, etc.) due todesign constraints of the mobile device. Such an optical sensor may notbe capable of capturing enough light during the image capture process,which may lead to a noisy, dark, washed out, flat, and/or improperlycolored captured image. Accordingly, when such a captured image is usedfor face recognition, the face recognition algorithms may not accuratelyrecognize the user in the captured image, and therefore the mobiledevice may not unlock successfully.

Certain aspects herein provide techniques for performing facerecognition of a user in low light conditions. Certain techniques aredescribed as performed by mobile device 100 of FIG. 1, however, itshould be noted that any suitable electronic device may be configured toperform the techniques described herein.

FIG. 3 illustrates example operations 300 for performing facerecognition that may be performed by an electronic device, in accordancewith aspects of the present disclosure. For example, operations 300 maybe performed by mobile device 100 (e.g., as controlled by processor110).

In certain aspects, at block 305, an electronic device initiates a facerecognition procedure. For example, in certain aspects, mobile device100 is configured to initiate a face recognition procedure based on aninput received at the mobile device 100. In particular, by onlyperforming face recognition when an input is received, as opposed tocontinuously performing face recognition, power may be saved at themobile device 100.

For example, when the mobile device 100 is locked (e.g., at a lockscreen) and a user presses a button (e.g., home button, power button,etc.) on the mobile device 100, the mobile device 100 begins performingface recognition. In another example, mobile device 100 may beconfigured to perform face recognition after receiving a voice commandfrom a user. In yet another example, mobile device 100 may include oneor more acceleration sensors, such as accelerometers, that measuremotion of the mobile device 100 relative to one or more axes. Theaccelerometers may be in the form of, for example,microelectromechanical system (MEMS) sensors. In some cases, anaccelerometer may be able to measure acceleration in multiple axes atonce, such as a two- or three-axis motion sensor. The accelerometers maydetect a user interacting with the mobile device 100, such as a usertapping on the mobile device 100 or picking up the mobile device 100 offof a surface. Mobile device 100 may be configured to perform facerecognition after detecting such a user interaction.

Continuing, at block 310, the electronic device determines if abrightness level (e.g., luminance/brightness) within a viewing area ofthe electronic device satisfies a threshold. For example, in certainaspects, processor 110 initially determines if a brightness level withina viewing area of optical sensor 105 satisfies a brightness threshold.

In certain aspects, mobile device 100, in addition to the optical sensor105, may include a light sensor (e.g., an ambient light sensor/detector)configured to measure light and send information indicative of themeasurement to processor 110. In certain aspects, the light sensor mayface the same direction as optical sensor 105. If the measurement (e.g.,luminance/brightness) is below the brightness threshold, a face may notbe detectable in an image captured by optical sensor 105, and thereforethe processor 110 may not be able to perform face recognition on theimage. Accordingly, in certain aspects, if the measurement of thebrightness level from the light sensor is below the brightnessthreshold, the processor 110 determines the brightness level does notsatisfy the brightness threshold. If the measurement of the brightnesslevel from the light sensor is equal to or above the brightnessthreshold, the processor 110 determines the brightness level satisfiesthe brightness threshold.

Alternatively or additionally to processor 110 determining if thebrightness level satisfies a brightness threshold based on a measurementfrom a light sensor, in certain aspects, processor 110 is configured toreceive a captured image from the optical sensor 105 and determinewhether the captured image satisfies a parameter threshold as indicativeof if the brightness level satisfies a brightness threshold (e.g.,different than or the same as the brightness threshold for the lightsensor). For example, in certain aspects, processor 110 is configured tocause optical sensor 105 to capture an image. In certain aspects,processor 110 is configured to control display 140 to display an imagecorresponding to the current view of the optical sensor 105 (e.g., inreal-time) during the image capture process. Accordingly, a user mayposition the view of the optical sensor 105 to include the face of theuser using visual feedback from the display 140. Optical sensor 105 isconfigured to send data indicative of the image to processor 110.

The processor 110 may be configured to determine whether the capturedimage is suitable for performing face recognition by determining if thecaptured image satisfies a parameter threshold as indicative of if thebrightness level satisfies a brightness threshold. In certain aspects,the processor 110 is configured to determine if one or more parameters(e.g., luminance, brightness, face contour detectability, etc.) of thecaptured image satisfy one or more respective parameter thresholds asindicative of if the brightness level satisfies a brightness threshold.

For example, processor 110 may be configured to determine whether aluminance/brightness of the image is greater than or equal to aparameter threshold. If the luminance/brightness is greater than orequal to the parameter threshold, the processor 110 may determine thecaptured image satisfies the parameter threshold and thus the brightnesslevel satisfies the brightness threshold. If the luminance/brightness isless than the parameter threshold, the processor 110 may determine thecaptured image does not satisfy the parameter threshold and thus thebrightness level does not satisfy the brightness threshold. For example,if the luminance/brightness is below the parameter threshold, a face maynot be detectable in the image, and therefore the processor 110 may notbe able to perform face recognition on the image.

In another example, the processor 110 is configured to determine if anyface is detectable in the image as a parameter threshold. For example,the processor 110 is configured to determine whether contours of a faceare detectable in the image, indicating that a face is present in theimage. If there is no face detectable in the image, the processor 110may not be able to perform face recognition on the image and theparameter threshold is not satisfied indicating the brightness leveldoes not satisfy the brightness threshold. If there is a face detectablein the image, the parameter threshold is satisfied indicating thebrightness level satisfies the brightness threshold.

If the electronic device determines the brightness level within theviewing area of the electronic device satisfies the threshold,operations 300 continue to block 320. If the electronic devicedetermines the brightness level within the viewing area of theelectronic device does not satisfy the threshold, operations 300continue to block 315.

At block 315, the electronic device is configured to increase aluminance of a light emitting component of the electronic device. Forexample, in certain aspects, the processor 110 is configured to controlillumination element 115 and/or display 140 to output a greater amountof light (e.g., increase brightness), thereby increasing a brightnesslevel in a viewing area of the optical sensor 105. Such an increase inthe brightness level may improve the quality of an image captured by theoptical sensor 105, thereby leading to a more accurate face recognitionusing the captured image.

In certain aspects, the processor 110 initially sets the luminanceoutput of illumination element 115 and/or display 140 at a minimum(e.g., minimum brightness, current brightness, off, etc.) after block305 and before block 310.

In certain aspects, the processor 110 is configured to incrementallyincrease the luminance output of illumination element 115 and/or display140, such as a by a fixed or variable increment. In certain aspects, forthe first iteration of block 315, the processor 110 is configured toincrease the luminance output of illumination element 115 and/or display140 based on a measured parameter (e.g., luminance/brightness) from theoptical sensor 105 and/or light sensor. For example, the processor 110may increase the output as a function of the measured parameter (in anamount proportional or based on the parameter).

In certain aspects, the processor 110 is configured to first increase aluminance output of the display 140 to a maximum level of display 140and only turns on or increases a luminance output of illuminationelement 115 after display 140 is at its maximum level.

After block 315, operations 300 return to block 310. In certain aspects,the electronic device iteratively goes from block 310 to block 315 andincrementally increase the luminance (e.g., from an initial firstluminance level to a final second luminance level) until the electronicdevice determines the brightness level within the viewing area of theelectronic device satisfies the threshold and operations 300 continue toblock 320.

At block 320, the electronic device captures an image including a faceof a user. For example, in certain aspects, processor 110 is configuredto cause optical sensor 105 to capture an image. In certain aspects,processor 110 is configured to control display 140 to display an imagecorresponding to the current view of the optical sensor 105 (e.g., inreal-time) during the image capture process. Accordingly, a user mayposition the view of the optical sensor 105 to include the face of theuser using visual feedback from the display 140. Optical sensor 105 isconfigured to send data indicative of the image to processor 110. Incertain aspects, after capturing the image, processor 110 is configuredto control illumination element 115 and/or display 140 to reduce itsluminance output to an initial luminance level (e.g., initial firstluminance level), minimum, etc.

Continuing, at block 325, the electronic device detects a face in theimage. For example, in certain aspects, processor 110 runs a facerecognition algorithm on the image, which in part detects a face in theimage.

Further, at block 330, the electronic device determines if the detectedface corresponds to an authorized user of the electronic device. Forexample, in certain aspects, processor 110 runs a face recognitionalgorithm on the image, which in part determines if the detected facecorresponds to an authorized user of the mobile device 100. For example,information indicative of one or more authorized users may be stored(e.g., securely, encrypted, etc.) on the mobile device 100 (e.g., inmemory 120) ore remotely accessible by the mobile device 100 (e.g., vianetwork interface 160). The face recognition algorithm may determine ifinformation indicative of the detected face corresponds to informationindicative of one or more authorized users. If the informationindicative of the detected face corresponds to information indicative ofone of the one or more authorized users, the processor 110 determinesthe detected face corresponds to an authorized user of the mobile device100. If the information indicative of the detected face does notcorrespond to information indicative of any of the one or moreauthorized users, the processor 110 determines the detected face doesnot correspond to an authorized user of the mobile device 100.

If at block 330, the electronic device determines the detected face doesnot correspond to an authorized user, operations 300 end. If at block330, the electronic device determines the detected face corresponds toan authorized user, operations 300 continue to block 335. At block 335,the electronic device unlocks. For example, processor 110 unlocks themobile device 100 so a user can interact with mobile device 100.

FIG. 4 illustrates example operations 400 for performing facerecognition that may be performed by an electronic device, in accordancewith aspects of the present disclosure.

At block 405, the electronic device determines if a brightness levelwithin a viewing area of the electronic device satisfies a threshold. Atblock 410, the electronic device increases a luminance output of theelectronic device from a first luminance level to a second luminancelevel when the brightness level does not satisfy the threshold. At block415, the electronic device captures an image at the second luminancelevel when the brightness level does not satisfy the threshold. At block420, the electronic device captures the image at the first luminancelevel when the brightness level satisfies the threshold. At block 425,the electronic device detects a face in the image. At block 430, theelectronic device determines if the face corresponds to an authorizeduser. At block 435, the electronic device unlocks the electronic devicewhen the face corresponds to an authorized user.

The methods disclosed herein comprise one or more steps or actions forachieving the methods. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112(f) unless the element is expressly recited using the phrase“means for” or, in the case of a method claim, the element is recitedusing the phrase “step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a wirelesscommunication device, a user interface (e.g., keypad, display, mouse,joystick, etc.) may also be connected to the bus. The bus may also linkvarious other circuits such as timing sources, peripherals, voltageregulators, power management circuits, and the like, which are wellknown in the art, and therefore, will not be described any further. Theprocessor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

What is claimed is:
 1. An electronic device comprising: an opticalsensor configured to capture one or more images within a viewing area ofthe optical sensor; a light emitting component; a dedicated illuminationelement; and a processor configured to: determine if a brightness levelwithin the viewing area of the optical sensor satisfies a threshold,wherein the brightness level satisfying the threshold comprises theoptical sensor detecting a face; if the brightness level does notsatisfy the threshold: increase a luminance of the light emittingcomponent from a first luminance level to a second luminance level, thesecond luminance level being a maximum luminance level of the lightemitting component; and control the optical sensor to capture an imageat the second luminance level, wherein if the second luminance leveldoes not satisfy the threshold, incrementally increasing a luminanceoutput of the dedicated illumination element until the brightness levelsatisfies the threshold; if the brightness level satisfies thethreshold: control the optical sensor to capture the image at the firstluminance level; detect the face in the image; determine if the facecorresponds to an authorized user; and unlock the electronic device whenthe face corresponds to the authorized user.
 2. The electronic device ofclaim 1, wherein the processor is configured to determine the brightnesslevel based on information from the optical sensor, wherein the opticalsensor comprises a camera.
 3. The electronic device of claim 1, furthercomprising a light sensor that is separate from the optical sensor,wherein the processor is configured to determine the brightness levelbased on information from the light sensor.
 4. The electronic device ofclaim 1, wherein the luminance of the light emitting component at thefirst luminance level is the light emitting component being off.
 5. Theelectronic device of claim 1, wherein to increase the luminance of thelight emitting component from the first luminance level to the secondluminance level comprises to: calculate a luminance level for the lightemitting component as a function of a brightness detected by at leastone of the optical sensor or a light sensor.
 6. The electronic device ofclaim 1, further comprising, if the brightness level does not satisfythe threshold, decreasing the luminance of the light emitting componentto the first luminance level after controlling the optical sensor tocapture the image at the second luminance level.
 7. The electronicdevice of claim 1, further comprising receiving a user input, whereindetermining the brightness level is based on receiving the user input.8. A method for performing face recognition in low light conditionsusing an electronic device, the method comprising: determining if abrightness level within a viewing area of the electronic devicesatisfies a threshold, wherein the brightness level satisfying thethreshold comprises detection of a face in the viewing area; increasinga luminance output of a light emitting component of the electronicdevice from a first luminance level to a second luminance level when thebrightness level does not satisfy the threshold, the second luminancelevel being a maximum luminance level of the light emitting component;capturing an image at the second luminance level when the brightnesslevel does not satisfy the threshold, wherein if the second luminancelevel does not satisfy the threshold, incrementally increasing aluminance output of a dedicated illumination element of the electronicdevice until the brightness level satisfies the threshold; capturing theimage at the first luminance level when the brightness level satisfiesthe threshold; detecting the face in the image; determining if the facecorresponds to an authorized user; and unlocking the electronic devicewhen the face corresponds to the authorized user.
 9. The method of claim8, further comprising determining the brightness level based oninformation from a camera.
 10. The method of claim 8, further comprisingdetermining the brightness level based on information from a sensorseparate from a camera used for capturing the image.
 11. The method ofclaim 8, wherein increasing the luminance output from the firstluminance level to the second luminance level comprises: calculating aluminance level as a function of a detected brightness.
 12. Anon-transitory computer readable medium having instructions storedthereon for causing an electronic device to perform a method forperforming face recognition in low light conditions, the methodcomprising: determining if a brightness level within a viewing area ofthe electronic device satisfies a threshold, wherein the brightnesslevel satisfying the threshold comprises detection of a face in theviewing area; increasing a luminance output of a light emittingcomponent of the electronic device from a first luminance level to asecond luminance level when the brightness level does not satisfy thethreshold, the second luminance level being a maximum luminance level ofthe light emitting component; capturing an image at the second luminancelevel when the brightness level does not satisfy the threshold, whereinif the second luminance level does not satisfy the threshold,incrementally increasing a luminance output of a dedicated illuminationelement of the electronic device until the brightness level satisfiesthe threshold; capturing the image at the first luminance level when thebrightness level satisfies the threshold; detecting the face in theimage; determining if the face corresponds to an authorized user; andunlocking the electronic device when the face corresponds to theauthorized user.
 13. The non-transitory computer readable medium ofclaim 12, wherein increasing the luminance output from the firstluminance level to the second luminance level comprises: calculating aluminance level as a function of a detected brightness.